Conventionally, for example, a storage blade is mounted in a rack of a server computer apparatus. A plurality of hard disk drives (HDDs) are inserted into a housing of the storage blade from front side of the housing in parallel. A front end of the HDD is received by an assisted panel that extends upward in parallel with the front side of the housing. For example, two control units that control the HDDs are inserted into the housing in parallel with the HDDs. Each of the control units includes a printed circuit board on which a connector is mounted at a front end of the printed circuit board. When the control unit is inserted into the housing from the front end of the control unit, the connector of the printed circuit board is received by a back panel that extends upward in parallel with the back side of the housing. An interconnecting board connects the back panel to the assisted panel. As a result, the HDDs are controlled by an electronic circuit component which is mounted on the printed circuit board.
Japanese Laid-open Patent Publication No. 9-171874 and No. 2008-47019 are examples in conventional technique.
The storage blade is connected to the large back panel arranged in the rack of the server computer apparatus. A connector which is mounted on the back panel in the housing of the storage blade is used to connect the storage blade to the large back panel. The connector is received by the large back panel. With the arrangement of the connector, a predetermined depth of the housing is secured. That is, the depth of the housing is determined according to the depth of the rack of the server computer apparatus. On the other hand, the depth of the HDD from the front side of the housing is smaller than the depth of the housing. As a result, a dead space is formed between the back side of the assisted panel and the back panel.